The present invention relates to a lighting system for use in a vehicle cabin.
FIG. 7 shows a known lighting system for use in a vehicle cabin. Referring to FIG. 7, a lamp 22 such as a room lamp for illuminating a cabin of an automotive vehicle 21 is generally arranged to a roof 23 at its center portion (or in the vicinity of the center portion). For providing light to seat cushions 24, 25, and floors 26, 27, etc. in the cabin, the lamp 22 is constructed in part or in its entirety by a material such as a resin having a diffuse transmission characteristic (see, for example, Japanese Utility Model First (unexamined) Publication No. 54-3759).
As a result, the roof 23 has a relatively light area at its center portion or in the vicinity of the lamp 22, and a relatively dark area at its portion distant from the lamp 22 or its peripheral portion.
On the other hand, the lamp 22, which is mounted to the roof 23 directly or indirectly through a reinforcing member, etc., often protrudes from the roof 23.
A problem faced in the known lighting system for use in a vehicle cabin is as follows:
When turning on, the lamp 22 provides light in the cabin. This light may reach eyes of a driver 29 after being reflected by a back mirror 28 as indicated by an arrow a in FIG. 7, or directly eyes of a passenger 30 as indicated by an arrow b in FIG. 7, causing glare and/or annoyance which results in difficulty of driving and discomfort. Additionally, the lamp 22 is directly visible from a follower vehicle, that is, light of the lamp 22 may directly reach eyes of a driver or a passenger in the follower vehicle as indicated by an arrow c in FIG. 7, causing glare and/or annoyance.
Thus, during night run of the vehicle 21, the lamp 22 is turned off in a general way. In that event, the full darkness may cause the driver 29 and the passenger 30, particularly, the latter, not only perception of narrowness but uneasiness in the cabin. These phenomena are also found when the passenger 30 takes a rest. Except when the passenger 30 falls into a deep sleep, it is preferable that the illuminance is not null in the cabin. This will be understood from the fact that, at night, lighting equipments in a bedroom are kept turned on in part to obtain a reduced level of illuminance (use of a night light), and not turned off in their entirety.
It is, therefore, an object of the present invention to provide a lighting system for use in a vehicle cabin which is free from glare and/or annoyance, and makes easy and calm a driver and a passenger particularly when taking a rest.